戊二醛交联改性鼠尾I型胶原纤维的结构与性能研究

以自制的鼠尾I型胶原为原料,经湿法纺丝制备胶原纤维,采用戊二醛蒸气对胶原纤维进行交联改性处理,对交联改性前后纤维的结构和性能进行了表征。结果表明:经戊二醛交联改性处理后,胶原纤维的断裂强度得到提高,与未交联胶原纤维相比,交联处理20 min的胶原纤维断裂强度提高了15.8%;交联改性胶原纤维抗水性明显提高,交联20 min后,吸水率明显减小且趋于稳定;戊二醛在胶原纤维表面发生了化学反应,交联改性胶原纤维的三股螺旋结构的稳定性和热稳定性提高。     

凝固浴温度对再生细菌纤维素纤维结构与性能的影响

以细菌纤维素为原料,N-甲基吗啉-N-氧化物为溶剂制得纺丝原液,在不同的凝固浴温度条件下,制备再生细菌纤维素纤维,对其形貌、结晶度、取向度、力学性能、吸湿保湿性等进行了研究.结果表明:随着凝固浴温度的提高,再生细菌纤维素纤维表面逐渐趋于光滑,且结晶度提高、取向度和断裂强度降低;凝固浴温度为0～45℃,再生细菌纤维素纤维...     

凝固浴温度对Ionicell纤维结构及性能的影响

以离子液体1-丁基-3-甲基咪唑氯盐([BMIM]Cl)为溶剂,水为凝固浴,α-纤维素质量分数95.5%的棉浆为原料,通过干湿法纺丝制备再生纤维素(Ionicell)纤维。探讨了凝固浴温度对纤维结晶结构以及力学性能的影响。结果表明:在其他相同条件下,随着凝固浴温度的升高,纤维的结晶度、双折射和非晶区取向都呈现先增大后减小的趋势,纤维的断裂强度、初始摸量也呈先增大后减小的趋势,当凝固浴温度为20℃时纤维的力学性能最佳,断裂强度为2.98 cN/dtex,断裂伸长率为3.5%,初始模量为59.7 cN/dtex。     

丙烯酸接枝改性壳聚糖纤维的制备及性能

在引发剂过硫酸铵(APS)的作用下,采用丙烯酸(AA)接枝改性壳聚糖(CS),制备出CS-AA接枝共聚物,经湿法纺丝将其纺制成纤维,再用戊二醛对纤维进行一定程度的交联,可得到较好力学性能的改性CS纤维。结果表明:CS质量分数(相对AA)为14.3%,APS(相对AA)的摩尔分数为1.0%,反应温度65℃,反应时间6 h,凝固浴中无水乙醇和质量分数为10%氢氧化钠水溶液的体积比为50/50。在此条件下制得的纤维的断裂强度为0.55 cN/dtex,断裂伸长率为367%,经交联处理后纤维的断裂强度达2.03 cN/dtex。     

改性纤维素微球的制备及其对Pb2＋吸附性能的研究

利用绿色环保的碱／尿素／水溶剂体系直接制备纤维素溶液共混聚乙烯亚胺（PEI）,然后通过高压静电法制备再生纤维素微球,并与戊二醛交联固定化,制备了复合型吸附材料。借助吸附动力学和吸附等温方程研究了改性纤维素微球对Pb2＋的吸附性能,结果表明改性纤维素微球对Pb2＋具有较好的吸附容量达到9．46mg／g,相比空白微球提高50％以上,并且吸附过程符合准二级动力学方程和Freundlich等温方程。     

戊二醛交联乙烯—乙烯醇非织造布的制备及研究

采用高压静电纺丝技术,以DMAc为溶剂,经戊二醛交联改性制备了戊二醛交联乙烯-乙烯醇(EVOH)非织造布。通过扫描电子显微镜(SEM)、热失重分析(TG)对其微观形貌、耐热性进行了研究,并分析了戊二醛交联EVOH非织造布的横向拉伸强度。结果表明:经戊二醛交联改性后,纤维直径变大,出现扭转和弯曲,并且发生了纤维间局部粘结现象;TG分析表明,经戊二醛交联改性后的EVOH非织造布的耐热性提高;戊二醛交联EVOH非织造布横向拉伸强度为97.90MPa,明显大于纯EVOH非织造布的横向拉伸强度。     

香精微胶囊与再生纤维素的相容性

芳香型再生纤维素纤维是利用再生纤维素与香味精油或香料融合,制成纺丝原液,然后进行纺丝制得芳香型再生纤维素纤维。采用β-环糊精对香精分子进行包覆制得β-环糊精/香精微胶囊来改善香精与再生纤维素的相容性,将制得的微胶囊放在尼康显微镜及扫描电镜下观察并测试其相容性能。结果表明:香精微胶囊在100℃沸水、酸性条件和碱性条件下颗粒没有明显的变化,说明其具有良好的热稳定性、耐酸性及耐碱性,适合生产芳香型再生纤维素纤维。     

凝固条件对纤维素/丝素蛋白纤维相形态及性能的影响

蛋白质纤维具有光滑柔顺、透气吸湿等优点,然而天然蛋白纤维产量有限。再生蛋白纤维的制备通常采用与其它成纤高分子接枝或共混的方法,有利于提高再生蛋白纤维的断裂强度。选用同为天然高分子的纤维素为基体,以共溶剂溶解纤维素与蛋白质,进而纺丝成形制得力学性能满足要求的纤维素/丝素蛋白共混纤维。为了探究凝固剂组成对纤维素/丝素蛋白共混纤维相形态及性能的影响,选用水、乙醇、乙醇/1-丁基-3-甲基咪唑氯盐([BMIM]Cl)等作为凝固剂。研究发现:乙醇作为凝固剂时,纤维素与丝素蛋白能很好地同时凝固;而当在乙醇凝固浴中加入适量的[BMIM]Cl径向均匀分散。通过对凝固剂组成的调控能有效提升纤维的力学强度。     

离子液体法新型再生纤维素纤维的研究

采用离子液体1-乙基-3-甲基咪唑醋酸盐([EMIM]Ac)为溶剂,制备了纤维素/[EMIM]Ac溶液,研究了该体系的流变性能,利用干喷湿纺的方式制备的新型再生纤维素纤维,并对纤维的结构与性能进行了分析。结果表明,纤维素/[EMIM]Ac溶液为典型的切力变稀流体,在较高剪切速率下,纺丝溶液的黏度变化较小;由该体系制备的新型再生纤维素纤维具有纤维素Ⅱ晶型的结构;随着拉伸比的提高,纤维的取向程度及结晶度增大,纤维力学性能提高。以离子液体为溶剂制备的再生纤维素纤维表面光滑,质地紧密。     

TAHT交联对Lyocell纤维抗原纤化性能的影响

采用1,3,5-三丙烯酰基-六氢化-1,3,5-三嗪(TAHT)交联后处理的方法提高Lyocell纤维的抗原纤化性能;用湿摩擦值表征纤维的抗原纤化能力,研究了TAHT交联条件对Lyocell纤维抗原纤化能力及力学性能的影响规律。结果表明:最佳实验条件为采用交联剂和催化剂分别溶解、共同浸渍纤维的方法,TAHT质量浓度30 g/L,交联温度70℃,浸渍时间3 min,汽蒸时间3 min,磷酸三钠质量浓度20 g/L;改性后的Lyo-cell纤维抗原纤化能力提高100倍以上,断裂强度下降18%;红外光谱表明Lyocell纤维与TAHT发生了迈克尔加成反应,生成二次价键,使纤维的抗原纤化能力明显提高。     

Ozone treatment for improving the solubility of cellulose extracted from palm fiber

We investigated effects of ozone treatment on solubility of cellulose and chemical composition in cellulose extracted from palm fiber. The initial holocellulose, α-cellulose, and lignin contents of the extracted cellulose were 88.0, 81.9, and 8.75%, respectively. The extracted cellulose was treated with ozone and NaOH solution. Ozone treatment for 5 hr at 40°C using 3% citric acid decreased the lignin content from 8.75 to 2.71%. Under these conditions, the degree of polymerization (DP) of the cellulose decreased to 29 from 160 and the carboxyl content increased to 2.05 mmol/g. When the solid phase was treated with NaOH after ozone treatment, the mass of the solid phase decreased as the ozone treatment time increased. The lowest mass was 0.43 g. Additionally, the mass of cellulose regenerated from the liquid phase increased with increasing treatment time. The highest mass of regenerated cellulose was 0.54 g. The masses of the solid phase and regenerated cellulose obtained without ozone treatment under the same conditions were 0.76 and 0.18 g, respectively. These results suggest that ozone treatment improves the solubility of cellulose by converting hydroxyl groups in the cellulose to carboxyl groups and reducing the DP.     

抗菌再生纤维素纤维的制备与表征

利用实验室合成的非水溶性抗菌剂——聚六亚甲基胍十二烷基苯磺酸盐(PHGDBS),与纤维素共同溶解于离子液体中,经干喷湿纺制备了抗菌再生纤维素纤维,并研究了PHGDBS对纤维结构性能的影响。结果表明:所合成的PHGDBS能够溶解于离子液体中,且对细菌和真菌均有很好的抗菌效果。PHGDBS质量分数为2%时制备的再生纤维素纤维,对金黄色葡萄球菌和大肠埃希菌的抗菌率分别达99.7%和94.5%;经水洗15次后,抗菌率仍保持在90%以上。另外,PHGDBS的加入对纤维的表面和截面形态无显著影响,虽然再生纤维素纤维的结晶度和取向度减小,纤维的断裂强度有所下降,但仍可以满足服用性能。     

离子液体法制备再生细菌纤维素纤维

以离子液体(氯化1-甲基-3-正丁基咪唑)溶解高聚合度细菌纤维素(BC),采用湿法纺丝制备再生细菌纤维素(RBC)初生纤维;通过红外光谱分析(FTIR)、广角X射线衍射(WAXD)分析、热失重(TG)分析、扫描电镜( SEM)、单丝强度拉伸等表征了RBC初生纤维的结构和性能.结果表明:该溶剂体系通过10 h的快速搅拌溶...     

Regenerated cellulose membrane prepared with ionic liquid 1‐butyl‐3‐methylimidazolium chloride as solvent using wheat straw

BACKGROUND: Currently, cellulose membranes are prepared by cellulose acetate hydrolysis or chemical derivatization dissolution and regeneration using cotton pulp or wood pulp. In this study, the concept ‘lignocelluloses biorefinery’ was used, and good quality long fiber was fractionated from wheat straw using clean technologies. The objective of this study is to develop wheat straw cellulose to prepare regenerated cellulose membrane with ionic liquid 1‐butyl‐3‐methylimidazolium chloride ([BMIM]Cl) as solvent. RESULTS: Wheat straw cellulose (WSC) fractionated from wheat straw contained 93.6% α‐cellulose and the degree of polymerization (DP) was 580. WSC was dissolved directly without derivatization in [BMIM]Cl. With increase in dissolving temperature, the DP of the regenerated cellulose dropped, which resulted in a decrease in the intensity of regenerated cellulose membrane. After regeneration in [BMIM]Cl, the WSC transformed from cellulose I to cellulose II, and the crystallinity of the regenerated cellulose was lower than the original cellulose. The regenerated WSC membrane had good mechanical performance and permeability, the tensile strength and breaking elongation were 170 MPa and 6.4%, respectively, the pure water flux was 238.9 L m^?2 h^?1 at 0.3 MPa pressure, and the rejection of BSA was stabilized at about 97%. CONCLUSION: Wheat straw cellulose fractionated from wheat straw satisfied the requirement to prepare regenerated cellulose membrane using ionic liquid [BMIM]Cl as solvent. Copyright © 2012 Society of Chemical Industry     

硫酸水解对再生纤维素纤维葡萄糖转化率的影响

用浓硫酸水解竹浆、棉浆、木浆三种再生纤维素纤维,通过改变反应温度和时间,找出再生纤维素纤维水解葡萄糖得率最优的反应条件,并对不同种类的纤维素纤维水解液进行高效液相色谱分析。结果表明:当反应温度为50℃、反应时间为120 min时,竹浆再生纤维素纤维的葡萄糖转化率可达75%;在高效液相色谱中,竹浆再生纤维素纤维在7 min的位置有较明显的出峰,在12.5～14.5 min的位置有一个双峰,有别于木浆、棉浆再生纤维素纤维。     

离子液体法纤维素纤维的制备及性能研究进展

对纤维素在离子液体中的溶解、溶解机理、纺丝原液的性质、纺丝工艺及纤维性能等进行了综述,认为离子液体作为一种新型纤维素溶剂,具有溶解速度快、溶解度大、对纤维素降解程度小、溶剂回收简单、回收率高等特点,且再生的纤维素具有良好的光泽和力学性能。     

Preparation and characterization of cellulose carbamate membrane with high strength and transparency

In this study, cellulose carbamate was synthesized from alkali cellulose and urea by a low-cost solid–liquid phase method. Cellulose carbamate was dissolved in cuprammonium solution to form a regenerated cellulose membrane with high strength and high transparency. The mass fraction of cellulose dissolved was greatly increased (up to 17%), and the thermal stability of cellulose was retained. The surface of the membrane is compact and there are regular microchannels in it. The factors influencing the transparency and mechanical properties of regenerated cellulose membrane were discussed by the range analysis of orthogonal experiment. The light transmittance is 95.50%, the breaking strength is 98.35 MPa, the elongation at break is 21.74%. The ability of heat preservation and moisture preservation of regenerated cellulose membrane was tested, and the effect was close to that of conventional polyethylene membrane. The membrane material has broad application prospects in packaging, food preservation, agriculture, and other fields.     

竹纤维素在NMMO中溶解再生前后的结构研究

以竹浆粕为原料、N-甲基吗啉-N-氧化物(NMMO)为溶剂,利用傅里叶红外光谱、X射线衍射、热重分析等着重研究了竹纤维素在NMMO中溶解前后结构的变化。研究发现:NMMO溶解纤维素过程属于物理过程,未发生衍生化反应,竹纤维素溶解后聚合度较溶解前有所降低,晶型由纤维素Ⅰ变成了纤维素Ⅱ;热重分析表明纤维素再生前后都具有较好的热稳定性。